Technical Field
The present invention relates to heteroepitaxy, and more particularly to devices and methods for employing crystal defect cancellation structures for epitaxially forming a crystal on non-lattice matched materials.
Description of the Related Art
High aspect ratio features with patterns and materials engineered so that selective area growth only occurs at a bottom of the features may help reduce defects during heteroepitaxy. This permits defects to terminate along sidewalls of the features. This type of defect reduction is called aspect ratio trapping (ART). Work has been done on controlling a seed area at the bottom of the high aspect ratio features at the bottom interfaces (e.g., making a V groove) to help control which defects and interfaces are active at relieving the strain and to trap the defects.
However, the trapping schemes and features attempted guide the fronts along only one or two growth fronts. This fails to address that in many crystal systems there are actually more crystallographic directions that are active for stacking faults and other defect generations.